Growth of several metropolitan areas, urban revitalization and the mobility of our society using vehicles has increased the need for an efficient transport infrastructure. The demand for parking is increasing and represents a major concern. Advanced Parking Management Systems (APMS) are used to assist motorists in finding parking spaces quickly. APMS can provide real-time information of parking space occupancy for several facilities. This information is used to generate parking availability messages that are displayed by message information boards through several different means.
System accuracy is a critical factor. The method used for vehicle counting is an important aspect of the APMS. Two types of systems are generally used for counting. The first one is based on entry/exit counters. Usually, inductive loop counters, RF tags and video detection are used. The second method is based on space occupancy detectors and use ultrasonic, inductive loop, infrared or microwave sensors. In that case, each sensing unit is installed over individual lot spaces and detects if the lot is available or not. Entry/exit counters are not as accurate as individual space sensors but are easier to implement. The installation of space sensors or the availability of mounting space for detectors in pre-existing parking facilities can be a problem. The ability to communicate data for each individual space is also an important issue to consider. The degree of complexity of the installation of the sensors can have an important impact on costs for an APMS and is another issue for these systems.
Some systems used for detecting available parking spaces use an emitter and a receiver. A signal is transmitted from the emitter to the receiver to detect an available space. When the receiver is hidden behind a vehicle, the signal will not be able to reach the receiver and the system will conclude that a vehicle is present. Other systems use optical sensors which read barcodes written on the pavement. When the optical sensor is not able to read the bar code, the system concludes that a vehicle is parked in the parking space.
In a vision-based system, each camera is able to survey more than one parking space. Some are able to identify features such as plate number, color, make and model of a vehicle. If such precision of detection is required, the performance of the camera is critical, notably in terms of resolution. Also, vision-based systems need a high bandwidth to communicate the data. Some smart cameras have an embedded processing system but are expensive. Other vision-based systems use stereoscopic principles to determine the occupancy of a parking space.
For all of these prior art solutions, costly installation is necessary. Typically, sensors and cameras must be mounted on walls, on a pillar, on a rail or must be embedded in the parking space. Prior art parking management systems are stand-alone systems that do not integrate within the current lighting infrastructure, using their own power line and, own cable interfaces. Some sensors are powered by batteries and require maintenance over time.